The invention relates to a device for detecting the installation of a child seat.
In vehicles that are equipped with an air bag on the passenger side or on the floor, the problem arises that whenever a child seat is installed there, tripping the air bag can cause injuries to the child in the child seat. It is therefore desirable for the installation of a child seat on applicable vehicle seat to be detected automatically.
According to the invention, a device for detecting the installation of a child seat, in particular on a vehicle seat, with one fixed part and one movable mechanism is furnished, in which the fixed part has a switch element with two switching states and means for forming an actuating field for the switch element, and the movable mechanism is movable as a result of the installation of a child seat from a first position to a second position, thus making a variation in the actuating field attainable, causing the switch element to change its switching state.
The device has the advantage that the switch element can be tripped reliably by the movable mechanism, and the movable mechanism is quite simple in design. In particular, field forming means and the switch element are disposed on the fixed part and can thus be [sic] reliably and in simple way on one another and are not subject to any motions whatever during operation. By means of the switch element, a signal can be switched that reminds the driver that the child seat has been installed, or sends information to the air bag controller as a result of which the applicable air bag is deactivated.
An embodiment in which the field is a magnetic field and the switch element is a magnetic switch element is especially advantageous. A magnetic field can be generated especially simply by means of a permanent magnet, in other words without supplying any energy whatever. The switching operation is also especially fast and reliable because of the use of a magnetic switch.
For varying the actuating magnetic field, a shielding means, in particular a sheet of soft iron, can advantageously be provided, which is located in the first position in a region between the magnetic switch element and the magnet and in the second position at least partly outside that region. In the first position, the shielding means short-circuits the actuating magnetic field. Because of its conductivity, a sheet of soft iron is especially well suited for this purpose. A shielding means for the actuating magnetic field represents an especially simple, reliable way of actuating the magnetic switch.
The magnetic switch element can have a so-called Reed switch. An embodiment by means of a Hall sensor is also conceivable.
Alternatively, the actuating field can also be an electromagnetic field, of the kind generated by a light source, for instance. The switch element in that case has a radiation detector, such as a photoelectric element.
In order to return the switch to its outset switching position again when the child seat is removed, means for restoring the movable mechanism to the first position can be provided.
In a variant of the invention, the movable mechanism is supported rotatably about a pivot point on the fixed part, and the shielding means is secured to the movable mechanism. In this variant, when the child seat is installed, the shielding means is pivoted from the first position, in which it shields the actuating magnetic field from the magnetic switch, into the second position, in which it at least partly uncovers the actuating magnetic field.
To achieve especially effective shielding, in this variant the shielding means can be deformed on at least one side in such a way that in the first position, it at least partly embraces one pole of the magnet.
If one edge of the shielding means is chamfered toward the pivot point, then particularly precise switching of the magnetic switch can be achieved.
It is also advantageous if the fixed part on its underside has a dirt removal slot, which is at least partly engaged by the shielding means. Then dirt, which over the course of time gets into the device and collects on its underside, can be moved out of the device by the moving shielding means.
The restoring means, in the first variant, can have a torsion spring that is disposed coaxially with the movable mechanism.
In another variant, the movable mechanism has one rotatable part and one displaceable part, and the rotatable part is supported rotatably about a pivot point on the fixed part, and the displaceable part has the shielding means, and the displaceable part is displaceable from the first position to the second position by means of a cam that is located on the rotatable part. This variant can be made in an especially space-saving form.
In this variant, the restoring means can have [sic] which acts on the displaceable part, and/or can have a torsion spring which is disposed coaxially with the rotatable part and acts on it.
In both variants, the fixed part can have two housing halves, which are preferably provided with a number of fixation pins and associated openings for radial fixation of the two housing halves relative to one another.
The two housing halves can also have positive-displacement dogs and associated openings for axially fixing the housing halves relative to one another.
According to the invention, the magnetic switch element can be designed for switching a signal for an air bag controller. This makes it possible to attain an automatic shutoff of the air bag controller in the event that an installed child seat is detected.
It is especially advantageous if the movable mechanism has a lever that is movable by means of a locking device of the child seat. A locking device of this kind is present in any case in certain child seats, so that those child seats require no modification.
It is also advantageous if means for securing in the vehicle seat on a crossbar, in particular in accordance with ISO standard 13216-1 (xe2x80x9cISOFixxe2x80x9d) are provided.
The invention further includes a vehicle seat that has at least one of the above-described detecting devices.